1. Field of the Invention
The present invention relates to an apparatus, a method, and a computer program product for generating an interpolated image to be inserted between a source image and a destination image.
2. Description of the Related Art
An example of a technique for smoothing moving images by generating an interpolated image to be interpolated between a source image and a destination image among the moving images is disclosed in JP-A 2007-74590 (KOKAI). According to this conventional technique, inconsistency among the motion vectors assigned to an inserted frame to be inserted between the source image and the destination image and the activities of interpolated images are calculated so that it is judged whether the interpolated images are to have a failure, based on the inconsistency among the motion vectors and the activities. Further, a 0-vector interpolated image is generated from a frame t and a frame t+1, and a blending ratio with which the 0-vector interpolated image is to be blended into the inserted frame is determined, so that the 0-vector interpolated image is blended into a failure portion according to the determined blending ratio.
According to the technique disclosed in JP-A 2007-74590 (KOKAI), a still image is used as a failure-preventing image that prevents the interpolated frame from having a failure caused by, for example, motion vectors having an error. Further, according to this technique, a reliability level of each of the motion vectors is calculated so that, based on the calculated reliability levels, a motion compensated image is used in an area in which the motion vector is reliable, whereas a still image is blended into an area in which the motion vector is not reliable. Thus, the robustness of the interpolated images is improved.
This conventional technique is based on an assumption that the motion vectors are not reliable, but the still image is reliable. There are many situations, however, in which this assumption does not hold true. For example, in the case where the image contains an object that moves (hereinafter, a “moving object”), if some of the motion vectors of the moving object has an error, the levels of reliability of these motion vectors are not so high. Accordingly, a large amount of the still image will be blended. As a result, the still image is blended into a part of the moving object, and the part with the still image is viewed as an artifact. Thus, a problem arises where it is not possible to generate interpolated images that are robust and have high quality.